Nex 6 just not sharp?

Here are 3 images I took. 1 with the Canon 7d, and one with a Panasonic LX5. Both these look very sharp especially if you zoom into the eyes a bit. The last one with the NEX6 doesnt look like it focussed quite right on the face (and this is the same for most of ther pictures I took with the NEX6, both auto focus and manual, although everything confirmed focus at the time.

Canon 7d iso 400 f4

NEX6 iso 100 f8

Panasonic LX5 iso 100 f 5.6

). Also it looks a little "cold". Would an 81 filter be worth a try as well?